I believe mine too is Royal - the pin in the 5C (yes, I had it backwards, was tired) is a rectangular piece like a key, with a small round pin that goes into a hole in the adapter that fits into the 5 MT adapter - The key part is almost worn off - I presume that I could make one, but this is one of those little things that would take forever and it's just gotta be pretty inexpensive compared to a day's work. I have heard of folks getting a bag of them somehow. maybe contacting Royal is the way to go.